TH9 cells in anti-tumor immunity

Inborn errors of immunity reveal molecular requirements for generation and maintenance of human CD4+ IL-9-expressing cells

BACKGROUND

CD4+ T cells play essential roles in adaptive immunity. Distinct CD4+ T-cell subsets-TH1, TH2, TH17, TH22, T follicular helper, and regulatory T cells-have been identified, and their contributions to host defense and immune regulation are increasingly well defined. IL-9-producing TH9 cells were first described in 2008 and appear to play both protective and pathogenic roles in human immunity. However, key requirements for generating human TH9 cells remain incompletely defined.

OBJECTIVE

We sought to define signaling pathways that regulate IL-9 production by human CD4+ T cells.

METHODS

Human naive and memory CD4+ T cells were cultured under different conditions, and the molecular mechanisms regulating IL-9 induction were determined by assessing the ability of CD4+ T cells from a broad range of patients (n = 92) with pathogenic variants in key immune genes (n = 21) to differentiate into IL-9+ cells.

RESULTS

We identified 2 culture conditions that yielded IL-9-expressing cells from naive CD4+ T cells and amplified IL-9 production by in vivo-generated memory CD4+ T cells: TGF-β plus IL-4 (ie, TH9 polarizing condition), and the combination of IL-21, IL-23, IL-6, IL-1β, and TGF-β (ie, TH17 polarizing condition). Combining these conditions had a synergistic effect in generating IL-9+CD4+ T cells. IL-9 induction required STAT3-activating cytokines as well as intact signaling via the T-cell receptor and STAT5. Importantly, IL-9 induction was restrained by IFN-γ/STAT1 and IL-10.

CONCLUSIONS

Our findings revealed critical molecules involved in inducing/restraining IL-9 production by human CD4+ T cells, thereby identifying pathways that could be targeted to modulate IL-9 in health and disease.

GITRL enhances cytotoxicity and persistence of CAR-T cells in cancer therapy

Chimeric antigen receptor (CAR)-T cell therapy has achieved remarkable clinical success in treating hematological malignancies. However, its clinical efficacy in solid tumors is less satisfactory, partially due to poor in vivo expansion and the limited persistence of CAR-T cells. Here, we demonstrated that the overexpression of GITR ligand enhances the anti-tumor activity of CAR-T cells. Compared to prostate-specific membrane antigen-BB-Z (PSMA-BB-Z) CAR-T, PSMA-BB-Z-GITRL CAR-T cells have much more interferon (IFN)-γ, TNF-α, and interleukin (IL)-9 secretion, a higher proportion of central memory T (TCM) cells and T helper 9 (Th9) cells, less expression of exhaustion markers, and robust proliferation capacity. Consequently, PSMA-BB-Z-GITRL CAR-T cells exhibited more potent anti-tumor activity against established solid tumors in vivo than PSMA-BB-Z CAR-T cells. The results of the in vivo persistence experiment also indicated that PSMA-BB-Z-GITRL CAR-T cells exhibited much more retention in mouse blood, spleen, and tumor tissue than PSMA-BB-Z CAR-T cells 15 days after CAR-T cell therapy. In addition, PSMA-BB-Z-GITRL CAR-T cells produce higher levels of IFN-γ, TNF-α, and IL-9 in mouse blood, exhibiting a higher proportion of TCM cells and a lower proportion of Treg cells compared to PSMA-BB-Z CAR-T cells. Our results demonstrate that the overexpression of GITRL has important implications for improving CAR-T cell-based human solid tumor immunotherapy.

Tumor Antigen-Tethered Spiked Virus-Like- Poly(Lactic-Co-Glycolic Acid)-Nanoparticle Vaccine Enhances Antitumor Ability Through Th9 Promotion in Mice

Purpose

Immunotherapy emerges as a promising frontier in cancer therapy and prevention. This study investigates the capacity of tumor-antigenic nanoparticles, specifically ovalbumin-tethered spiked virus-like poly(lactic-co-glycolic acid) nanoparticles (OVA-sVLNP), to effectively elicit humoral and cellular immune responses against tumors.

Methods

OVA-sVLNP were synthesized through thiol-maleimide crosslinking using a single emulsion method. Comprehensive characterization was performed through Nuclear Magnetic Resonance (NMR), dynamic light scattering, Cryo-electron microscopy (Cryo-EM), confocal microscopy, and flow cytometry. Immunogenicity was evaluated using an enzyme-linked immunosorbent assay (ELISA) for quantifying immunoglobulin levels (IgG, IgG1, IgG2a) and cytokines in mouse sera. Flow cytometry profiled cellular immune responses in mouse spleens, and organ biosafety was assessed using immunohistochemistry and hematoxylin and eosin (H&E) staining.

Results

OVA-sVLNP had a mean particle size of 193.8 ± 11.9 nm, polydispersity index of 0.307 ± 0.04, and zeta potential of -39.6 ± 10.16 mV, remaining stable for one month at 4°C. In vitro studies revealed significant upregulation of CD80/CD86 in dendritic cells, indicating robust activation. In vivo, the optimal concentration (V25) induced potent IgG, IgG1, and IgG2a antibodies, significant populations of CD3+CD4+, CD3+CD8+, and a rare subset of CD3+CD4+CD8+ memory T cells. Notably, Th9 induction resulted in the secretion of IL-9, IL-10, and other cytokines, which are crucial for orchestrating cytotoxic T cell activity and antitumor effects. Overall, higher doses did not improve outcomes, highlighting the significance of optimal dosing.

Conclusion

This study demonstrated potent immunogenicity of OVA-sVLNP, characterized by the induction of specific IgG antibodies and the stimulation of cellular immune responses, particularly tumor-killing Th9 cells. The simplicity and cost-effectiveness of the manufacturing process augment the potential of OVA-sVLNP as a viable candidate for antitumor vaccines, opening new avenues for cancer prevention and cell-based therapeutic strategies.

Th17 cell function in cancers: immunosuppressive agents or anti-tumor allies?

T helper (Th) 17 cells, a distinct subset of Th lymphocytes, are known for their prominent interleukin (IL)-17 production and other pro-inflammatory cytokines. These cells exhibit remarkable plasticity, allowing them to exhibit different phenotypes in the cancer microenvironment. This adaptability enables Th17 cells to promote tumor progression by immunosuppressive activities and angiogenesis, but also mediate anti-tumor immune responses through employing immune cells in tumor setting or even by directly converting toward Th1 phenotype and producing interferon-gamma (IFN-γ). This dual role of Th17 cells in cancer makes it a double-edged sword in encountering cancer. In this review, we aim to elucidate the complexities of Th17 cell function in cancer by summarizing recent studies and, ultimately, to design novel therapeutic strategies, especially targeting Th17 cells in the tumor milieu, which could pave the way for more effective cancer treatments.

Activin A Promotes Differentiation of a Pathogenic Multicytokine IL-9-secreting CD4+ T Cell Population

The development of Th subsets results from cellular and cytokine cues that are present in the inflammatory environment. The developing T cell integrates multiple signals from the environment that sculpt the cytokine-producing capacity of the effector T cell. Importantly, T cells can discriminate similar cytokine signals to generate distinct outcomes, and that discrimination is critical in Th subset development. IL-9-secreting Th9 cells regulate multiple immune responses, including immunity to pathogens and tumors, allergic inflammation, and autoimmunity. In combination with IL-4, TGF-β or activin A promotes IL-9 production; yet, it is not clear if both TGF-β family members generate Th9 cells with identical phenotype and function. We observed that in contrast to TGF-β that efficiently represses Th2 cytokines in murine Th9 cultures, differentiation with activin A produced a multicytokine T cell phenotype with secretion of IL-4, IL-5, IL-13, and IL-10 in addition to IL-9. Moreover, multicytokine secreting cells are more effective at promoting allergic inflammation. These observations suggest that although TGF-β and IL-4 were identified as cytokines that stimulate optimal IL-9 production, they might not be the only cytokines that generate optimal function from IL-9-producing T cells in immunity and disease.

Immunocytes interact directly with cancer cells in the tumor microenvironment: one coin with two sides and future perspectives

The tumor microenvironment is closely linked to the initiation, promotion, and progression of solid tumors. Among its constitutions, immunologic cells emerge as critical players, facilitating immune evasion and tumor progression. Apart from their indirect impact on anti-tumor immunity, immunocytes directly influence neoplastic cells, either bolstering or impeding tumor advancement. However, current therapeutic modalities aimed at alleviating immunosuppression from regulatory cells on effector immune cell populations may not consistently yield satisfactory results in various solid tumors, such as breast carcinoma, colorectal cancer, etc. Therefore, this review outlines and summarizes the direct, dualistic effects of immunocytes such as T cells, innate lymphoid cells, B cells, eosinophils, and tumor-associated macrophages on tumor cells within the tumor microenvironment. The review also delves into the underlying mechanisms involved and presents the outcomes of clinical trials based on these direct effects, aiming to propose innovative and efficacious therapeutic strategies for addressing solid tumors.

Combination of percutaneous thermal ablation and adoptive Th9 cell transfer therapy against non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is one of the predominant malignancies globally. Percutaneous thermal ablation (PTA) has gained widespread use among NSCLC patients, with the potential to elicit immune responses but limited therapeutic efficacies for advanced-stage disease. T-helper type 9 (Th9) cells are a subset of CD4+ effector T cells with robust and persistent anti-tumor effects. This study proposes to develop PTA-Th9 cell integrated therapy as a potential strategy for NSCLC treatment.

METHODS

The therapeutic efficacies were measured in mice models with subcutaneously transplanted, recurrence, or lung metastatic tumors. The tumor microenvironments (TMEs) were evaluated by flow cytometry. The cytokine levels were assessed by ELISA. The signaling molecules were determined by quantitative PCR and Western blotting. The translational potential was tested in the humanized NSCLC patient-derived xenograft (PDX) model.

RESULTS

We find that PTA combined with adoptive Th9 cell transfer therapy substantially suppresses tumor growth, recurrence, and lung metastasis, ultimately extending the survival of mice with NSCLC grafts, outperforming both PTA and Th9 cell transfer monotherapy. Analysis of TMEs indicates that combinatorial therapy significantly augments tumor-infiltrating Th9 cells, boosts anti-tumor effects of CD8+ T cells, and remodels tumor immunosuppressive microenvironments. Moreover, combinatorial therapy significantly strengthens the regional and circulation immune response of CD8+ T cells in mice with tumor lung metastasis and induces peripheral CD8+ T effector memory cells in mice with tumor recurrence. Mechanically, PTA reinforces the anti-tumor ability of Th9 cells primarily through upregulating interleukin (IL)-1β and subsequently activating the downstream STAT1/IRF1 pathway, which could be effectively blocked by intercepting IL-1β signaling. Finally, the enhanced therapeutic effect of combinatorial therapy is validated in humanized NSCLC PDX models.

CONCLUSIONS

Collectively, this study demonstrates that combinatorial therapy displays robust and durable anti-tumor efficacy and excellent translational potential, offering excellent prospects for translation and emerging as a promising approach for NSCLC treatment.

Regulatory role of T helper 9/interleukin-9: Transplantation view

T helper 9 (Th9) cells, a subset of CD4+ T helper cells, have emerged as a valuable target for immune cell therapy due to their potential to induce immunomodulation and tolerance. The Th9 cells mainly produce interleukin (IL)-9 and are known for their defensive effects against helminth infections, allergic and autoimmune responses, and tumor suppression. This paper explores the mechanisms involved in the generation and differentiation of Th9 cells, including the cytokines responsible for their polarization and stabilization, the transcription factors necessary for their differentiation, as well as the role of Th9 cells in inflammatory and autoimmune diseases, allergic reactions, and cancer immunotherapies. Recent research has shown that the differentiation of Th9 cells is coregulated by the transcription factors transforming growth factor β (TGF-β), IL-4, and PU.1, which are also known to secrete IL-10 and IL-21. Multiple cell types, such as T and B cells, mast cells, and airway epithelial cells, are influenced by IL-9 due to its pleiotropic effects.

Staphylococcus aureus-derived factors promote human Th9 cell polarization and enhance a transcriptional program associated with allergic inflammation

T helper (Th) 9 cells, characterized by robust secretion of IL-9, have been increasingly associated with allergic diseases. However, whether and how Th9 cells are modulated by environmental stimuli remains poorly understood. In this study, we show that in vitro exposure of human PBMCs or isolated CD4 T-cells to Staphylococcus (S.) aureus-derived factors, including its toxins, potently enhances Th9 cell frequency and IL-9 secretion. Furthermore, as revealed by RNA sequencing analysis, S. aureus increases the expression of Th9-promoting factors at the transcriptional level, such as FOXO1, miR-155, and TNFRSF4. The addition of retinoic acid (RA) dampens the Th9 responses promoted by S. aureus and substantially changes the transcriptional program induced by this bacterium, while also altering the expression of genes associated with allergic inflammation. Together, our results demonstrate a strong influence of microbial and dietary factors on Th9 cell polarization, which may be important in the context of allergy development and treatment.

Amphiregulin/epidermal growth factor receptor/hypoxia-inducible factor-1α pathway regulates T helper 9 and T cytotoxic 9 cell response in adult patients with infectious mononucleosis

Amphiregulin (AREG)/epidermal growth factor receptor (EGFR) signaling induces hypoxia-inducible factor-1α (HIF-1α), leading to promotion of T helper 9 (Th9) differentiation and anti-tumor functions. However, the role of the AREG/EGFR/HIF-1α pathway in regulating interleukin-9 (IL-9) production by T cells in adult patients with infectious mononucleosis (IM) has not been fully elucidated. Fifty IM patients and 20 controls were enrolled. The percentages of Th9 and T cytotoxic 9 (Tc9) cells, the mRNA relative expressions of the transcription factors of IL-9-secreting T cells, purine-rich nucleic acid binding protein 1 (PU.1) and forkhead box protein O1 (FOXO1), and the levels of IL-9, AREG, EGFR, and HIF-1α were measured. Peripheral blood mononuclear cells from IM patients were stimulated with EGFR inhibitor or exogenous AREG in the presence or absence of anti-HIF-1α. Regulation of the AREG/EGFR/HIF-1α pathway to IL-9 production by T cells was assessed. The percentages of Th9 and Tc9 cells, plasma IL-9 levels, and PU.1 and FOXO1 mRNA expressions were elevated in IM patients. Plasma levels of AREG and HIF-1α were also increased in IM patients. AREG levels correlated positively with the percentages of Th9 and Tc9 cells in IM patients. Inhibition of EGFR suppressed IL-9-producing T cell differentiation and HIF-1α production. Exogenous AREG stimulation not only induced EGFR and HIF-1α expression but also promoted IL-9-secreting T cell differentiation. Neutralization of HIF-1α abrogated AREG/EGFR-induced Th9 and Tc9 differentiation in IM patients. The current data suggested that the AREG/EGFR/HIF-1α pathway contributed to the elevation of Th9 and Tc9 differentiation in IM patients.

The application of Interleukin-2 family cytokines in tumor immunotherapy research

The Interleukin-2 Family contains six kinds of cytokines, namely IL-2, IL-15, IL-4, IL-7, IL-9, and IL-21, all of which share a common γ chain. Many cytokines of the IL-2 family have been reported to be a driving force in immune cells activation. Therefore, researchers have tried various methods to study the anti-tumor effect of cytokines for a long time. However, due to the short half-life, poor stability, easy to lead to inflammatory storms and narrow safety treatment window of cytokines, this field has been tepid. In recent years, with the rapid development of protein engineering technology, some engineered cytokines have a significant effect in tumor immunotherapy, showing an irresistible trend of development. In this review, we will discuss the current researches of the IL-2 family and mainly focus on the application and achievements of engineered cytokines in tumor immunotherapy.

Systematic pan-cancer analysis showed that RAD51AP1 was associated with immune microenvironment, tumor stemness, and prognosis

Although RAD51 associated protein 1 (RAD51AP1) is crucial in genome stability maintenance, it also promotes cancer development with an unclear mechanism. In this study, we collected intact expression data of RAD51AP1 from the public database, and verified it was significantly over-expressed in 33 cancer types and correlated with poor prognosis in 13 cancer types, including glioma, adrenocortical carcinoma, lung adenocarcinoma. We further authenticated that RAD51AP1 is up-regulated in several typical cancer cell lines and promotes cancer cell proliferation in vitro. Moreover, we also demonstrated that RAD51AP1 was significantly positively related to cancer stemness score mRNAsi in 27 cancer types and broadly correlated to tumor-infiltrating immune cells in various cancers in a diverse manner. It was also negatively associated with immunophenoscore (IPS) and Estimation of STromal and Immune cells in MAlignant Tumours using Expression data (ESTIMATE) scores and positively correlated with mutant-allele tumor heterogeneity (MATH), tumor mutational burden (TMB), microsatellite instability (MSI), and PD-L1 expression in multiple cancers. The tumor stemness enhancing and tumor immune microenvironment affecting functions of RAD51AP1 might compose its carcinogenesis mechanism. Further investigations beyond the bioinformatics level should confirm these findings in each specific cancer.

IL-9 Producing Tumor-Infiltrating Lymphocytes and Treg Subsets Drive Immune Escape of Tumor Cells in Non-Small Cell Lung Cancer

Although lung cancer is the leading cause of cancer deaths worldwide, the mechanisms how lung cancer cells evade the immune system remain incompletely understood. Here, we discovered IL-9-dependent signaling mechanisms that drive immune evasion in non-small cell lung cancer (NSCLC). We found increased IL-9 and IL-21 production by T cells in the tumoral region of the lung of patients with NSCLC, suggesting the presence of Th9 cells in the lung tumor microenvironment. Moreover, we noted IL-9 producing Tregs in NSCLC. IL-9 target cells in NSCLC consisted of IL-9R+ tumor cells and tumor-infiltrating lymphocytes. In two murine experimental models of NSCLC, and in vitro, IL-9 prevented cell death and controlled growth of lung adenocarcinoma cells. Targeted deletion of IL-9 resulted in successful lung tumor rejection in vivo associated with an induction of IL-21 and reduction of Treg cells. Finally, anti-IL-9 antibody immunotherapy resulted in suppression of tumor development even in established experimental NSCLC and was associated with reduced IL-10 production in the lung. In conclusion, our findings indicate that IL-9 drives immune escape of lung tumor cells via effects on tumor cell survival and tumor infiltrating T cells. Thus, strategies blocking IL-9 emerge as a new approach for clinical therapy of lung cancer.

Alarmin Cytokines as Central Regulators of Cutaneous Immunity

Skin acts as the primary interface between the body and the environment. The skin immune system is composed of a complex network of immune cells and factors that provide the first line of defense against microbial pathogens and environmental insults. Alarmin cytokines mediate an intricate intercellular communication between keratinocytes and immune cells to regulate cutaneous immune responses. Proper functions of the type 2 alarmin cytokines, thymic stromal lymphopoietin (TSLP), interleukin (IL)-25, and IL-33, are paramount to the maintenance of skin homeostasis, and their dysregulation is commonly associated with allergic inflammation. In this review, we discuss recent findings on the complex regulatory network of type 2 alarmin cytokines that control skin immunity and highlight the mechanisms by which these cytokines regulate skin immune responses in host defense, chronic inflammation, and cancer.

Pathogen size alters C-type lectin receptor signaling in dendritic cells to influence CD4 Th9 cell differentiation

Dectin-1 recognizes β-glucan in fungal cell walls, and activation of Dectin-1 in dendritic cells (DCs) influences immune responses against fungi. Although many studies have shown that DCs activated via Dectin-1 induce different subsets of T helper cells according to different cytokine milieus, the mechanisms underlying such differences remain unknown. By harnessing polymorphic Candida albicans and polystyrene beads of different sizes, we find that target size influences production of cytokines that control differentiation of T helper cell subsets. Hyphal C. albicans and large beads activate DCs but cannot be phagocytosed due to their sizes, which prolongs the duration of Dectin-1 signaling. Transcriptomic analysis reveals that expression of Il33 is significantly increased by larger targets, and increased IL-33 expression promotes T_H9 responses. Expression of IL-33 is regulated by the Dectin-1-SYK-PLCγ-CARD9-ERK pathway. Altogether, our study demonstrates that size of fungi can be a determining factor in how DCs induce context-appropriate adaptive immune responses.

Oh et al. show that dendritic cells exposed to C. albicans hyphae more strongly induce IL-9-producing T cells compared with cells exposed to yeast. They find that this T_H9 response is driven in large part by Dectin-1 sensing microbe size, leading to elevated production of IL-33.

Human B Cells Mediate Innate Anti-Cancer Cytotoxicity Through Concurrent Engagement of Multiple TNF Superfamily Ligands

The essential innate immunity effector cells, natural killer and dendritic cells, express multiple plasma membrane-associated tumor necrosis factor (TNF) superfamily (TNFSF) ligands that, through simultaneous and synergistic engagement, mediate anti-cancer cytotoxicity. Here, we report that circulating B cells, mediators of adaptive humoral immunity, also mediate this innate anti-cancer immune mechanism. We show that resting human B cells isolated from peripheral blood induce apoptosis of, and efficiently kill a large variety of leukemia and solid tumor cell types. Single-cell RNA sequencing analyses indicate, and flow cytometry data confirm that B cells from circulation express transmembrane TNF, Fas ligand (FasL), lymphotoxin (LT) α1β2 and TNF-related apoptosis-inducing ligand (TRAIL). The cytotoxic activity can be inhibited by individual and, especially, combined blockade of the four transmembrane TNFSF ligands. B cells from tumor-bearing head and neck squamous cell carcinoma patients express lower levels of TNFSF ligands and are less cytotoxic than those isolated from healthy individuals. In conclusion, we demonstrate that B cells have the innate capacity to mediate anti-cancer cytotoxicity through concurrent activity of multiple plasma membrane-associated TNFSF ligands, that this mechanism is deficient in cancer patients and that it may be part of a general cancer immunosurveillance mechanism.

The Roles of IRF-8 in Regulating IL-9-Mediated Immunologic Mechanisms in the Development of DLBCL: A State-of-the-Art Literature Review

Interferon regulatory factor 8 (IRF-8) is a transcription suppressor that functions through associations with other transcription factors, contributing to the growth and differentiation of bone marrow cells and the activation of macrophages. IRF-8 expression profoundly affects pathogenic processes ranging from infections to blood diseases. Interleukin-9 (IL-9) is a multipotent cytokine that acts on a variety of immune cells by binding to the IL-9 receptor (IL-9R) and is involved in a variety of diseases such as cancer, autoimmune diseases, and other pathogen-mediated immune regulatory diseases. Studies have shown that IL-9 levels are significantly increased in the serum of patients with diffuse large B-cell lymphoma (DLBCL), and IL-9 levels are correlated with the DLBCL prognostic index. The activator protein-1 (AP-1) complex is a dimeric transcription factor that plays a critical role in cellular proliferation, apoptosis, angiogenesis, oncogene-induced transformation, and invasion by controlling basic and induced transcription of several genes containing the AP-1 locus. The AP-1 complex is involved in many cancers, including hematological tumors. In this report, we systematically review the precise roles of IL-9, IRF-8, and AP-1 in tumor development, particularly with regard to DLBCL. Finally, the recent progress in IRF-8 and IL-9 research is presented; the possible relationship among IRF-8, IL-9, and AP-1 family members is analyzed; and future research prospects are discussed.

Trophoblast-derived interleukin 9 mediates immune cell conversion and contributes to maternal-fetal tolerance

In the maternal-fetal crosstalk, fetal derived trophoblast cells can secret several molecules to regulate immune tolerance such as cytokines and chemokines, besides human leukocyte antigens (HLA) providing. However, the mechanism of these factors in pregnancy is still unknown. Our previous study showed that IL9 could be secreted by trophoblasts and exerted a positive effect on trophoblasts themselves through autocrine signaling. Given the immunoregulatory function of IL9 and its expression in trophoblasts, we hypothesize that IL9 contributes to maternal-fetal tolerance by regulating immune cells, especially CD14+ dendritic cells (DCs) and naïve CD4 + T cells who have essential roles in maternal-fetal immune tolerance. We performed a series of experiments, finding that HTR8/SVneo cells could secrete IL9 in vitro, and this secretion was decreased under hypoxia; both CD14 + DCs and naïve CD4 + T cells expressed IL9 receptors, indicating potential interactions among these cells. In CD14 + DCs, trophoblast-derived IL9 promoted the immature differentiation, and induced the secretion of Th2 cytokines, including IL4 and IL10, shifting the Th1/Th2 ratio to Th2. In naïve CD4 + T cells, IL9 also increased Foxp3 expression and promoted the secretion of Treg cytokines, including TGFβ and IL10, inhibiting pro-inflammatory Th17. Therefore, trophoblasts may act as fetal-derived immune cells to maintain maternal-fetal tolerance by secreting IL9. Given that trophoblast derived IL9 is decreased in preeclampsia, our study provides a new insight into maternal-fetal immunology and immunological disorders in abnormal pregnancy.

Tumor rejection in Cblb -/- mice depends on IL-9 and Th9 cells

BACKGROUND

Casitas B lymphoma-b (Cbl-b) is a central negative regulator of cytotoxic T and natural killer (NK) cells and functions as an intracellular checkpoint in cancer. In particular, Th9 cells support mast cell activation, promote dendritic cell recruitment, enhance the cytolytic function of cytotoxic T lymphocytes and NK cells, and directly kill tumor cells, thereby contributing to tumor immunity. However, the role of Cbl-b in the differentiation and antitumor function of Th9 cells is not sufficiently resolved.

METHODS

Using Cblb ^-/- mice, we investigated the effect of knocking out Cblb on the differentiation process and function of different T helper cell subsets, focusing on regulatory T cell (Treg) and Th9 cells. We applied single-cell RNA (scRNA) sequencing of in vitro differentiated Th9 cells to understand how Cbl-b shapes the transcriptome and regulates the differentiation and function of Th9 cells. We transferred tumor-model antigen-specific Cblb ^-/- Th9 cells into melanoma-bearing mice and assessed tumor control in vivo. In addition, we blocked interleukin (IL)-9 in melanoma cell-exposed Cblb ^-/- mice to investigate the role of IL-9 in tumor immunity.

RESULTS

Here, we provide experimental evidence that Cbl-b acts as a rheostat favoring Tregs at the expense of Th9 cell differentiation. Cblb ^-/- Th9 cells exert superior antitumor activity leading to improved melanoma control in vivo. Accordingly, blocking IL-9 in melanoma cell-exposed Cblb ^-/- mice reversed their tumor rejection phenotype. Furthermore, scRNA sequencing of in vitro differentiated Th9 cells from naïve T cells isolated from wildtype and Cblb ^-/- animals revealed a transcriptomic basis for increased Th9 cell differentiation.

CONCLUSION

We established IL-9 and Th9 cells as key antitumor executers in Cblb ^-/- animals. This knowledge may be helpful for the future improvement of adoptive T cell therapies in cancer.

The Janus Face of IL-33 Signaling in Tumor Development and Immune Escape

Simple Summary

Interleukin-33 (IL-33) is often released from damaged cells, acting as a danger signal. IL-33 exerts its function by interacting with its receptor suppression of tumorigenicity 2 (ST2) that is constitutively expressed on most immune cells. Therefore, IL-33/ST2 signaling can modulate immune responses to participate actively in a variety of pathological conditions, such as cancer. Like a two-faced Janus, which faces opposite directions, IL-33/ST2 signaling may play contradictory roles on its impact on cancer progression through both immune and nonimmune cellular components. Accumulating evidence demonstrates both pro- and anti-tumorigenic properties of IL-33, depending on the complex nature of different tumor immune microenvironments. We summarize and discuss the most recent studies on the contradictory effects of IL-33 on cancer progression and treatment, with a goal to better understanding the various ways for IL-33 as a therapeutic target.

Abstract

Interleukin-33 (IL-33), a member of the IL-1 cytokine family, plays a critical role in maintaining tissue homeostasis as well as pathological conditions, such as allergy, infectious disease, and cancer, by promoting type 1 and 2 immune responses. Through its specific receptor ST2, IL-33 exerts multifaceted functions through the activation of diverse intracellular signaling pathways. ST2 is expressed in different types of immune cells, including Th2 cells, Th1 cells, CD8⁺ T cells, regulatory T cells (T_reg), cytotoxic NK cells, group 2 innate lymphoid cells (ILC2s), and myeloid cells. During cancer initiation and progression, the aberrant regulation of the IL-33/ST2 axis in the tumor microenvironment (TME) extrinsically and intrinsically mediates immune editing via modulation of both innate and adaptive immune cell components. The summarized results in this review suggest that IL-33 exerts dual-functioning, pro- as well as anti-tumorigenic effects depending on the tumor type, expression levels, cellular context, and cytokine milieu. A better understanding of the distinct roles of IL-33 in epithelial, stromal, and immune cell compartments will benefit the development of a targeting strategy for this IL-33/ST2 axis for cancer immunotherapy.

Do TRIB1 and IL-9 Gene Polymorphisms Impact the Development and Manifestation of Pituitary Adenoma?

BACKGROUND/AIM

To evaluate the association between TRIB1(rs6987702) and IL-9(rs1859430, rs2069870) genotypes with the development and manifestation of pituitary adenoma (PA).

MATERIALS AND METHODS

The study group included 141 patients with PA and the control group consisted of 287 healthy people. The genotyping of rs6987702, rs1859430 and rs2069870 was carried out using a real-time polymerase chain reaction.

RESULTS

Statistically significant results were obtained regarding the rs1859430, but there were no significant results regarding rs6987702. We found that the rs1859430 A/A genotype increased the odds of having recurrent PA six times (p=0.006) under the co-dominant model and four times (p=0.021) under the recessive model. Furthermore, the analysis showed that the G/A genotype increased the odds of having recurrent PA 2.3 times (p=0.003) under the co-dominant model, while G/A and A/A genotypes increased the odds 2.7 times (p=0.011) under the over-dominant model.

CONCLUSION

Certain genotypes of rs1859430 can be associated with PA recurrence.

BFAR coordinates TGFβ signaling to modulate Th9-mediated cancer immunotherapy

TGFβ is essential for the generation of anti-tumor Th9 cells; on the other hand, it causes resistance against anti-tumor immunity. Despite recent progress, the underlying mechanism reconciling the double-edged effect of TGFβ signaling in Th9-mediated cancer immunotherapy remains elusive. Here, we find that TGFβ-induced down-regulation of bifunctional apoptosis regulator (BFAR) represents the key mechanism preventing the sustained activation of TGFβ signaling and thus impairing Th9 inducibility. Mechanistically, BFAR mediates K63-linked ubiquitination of TGFβR1 at K268, which is critical to activate TGFβ signaling. Thus, BFAR deficiency or K268R knock-in mutation suppresses TGFβR1 ubiquitination and Th9 differentiation, thereby inhibiting Th9-mediated cancer immunotherapy. More interestingly, BFAR-overexpressed Th9 cells exhibit promising therapeutic efficacy to curtail tumor growth and metastasis and promote the sensitivity of anti–PD-1–mediated checkpoint immunotherapy. Thus, our findings establish BFAR as a key TGFβ-regulated gene to fine-tune TGFβ signaling that causes Th9 induction insensitivity, and they highlight the translational potential of BFAR in promoting Th9-mediated cancer immunotherapy.

Vitamin D and Microbiota: Is There a Link with Allergies?

There is increasing recognition of the importance of both the microbiome and vitamin D in states of health and disease. Microbiome studies have already demonstrated unique microbial patterns in systemic autoimmune diseases such as inflammatory bowel disease, rheumatoid arthritis, and systemic lupus erythematosus. Dysbiosis also seems to be associated with allergies, in particular asthma, atopic dermatitis, and food allergy. Even though the effect of vitamin D supplementation on these pathologies is still unknown, vitamin D deficiency deeply influences the microbiome by altering the microbiome composition and the integrity of the gut epithelial barrier. It also influences the immune system mainly through the vitamin D receptor (VDR). In this review, we summarize the influence of the microbiome and vitamin D on the immune system with a particular focus on allergic diseases and we discuss the necessity of further studies on the use of probiotics and of a correct intake of vitamin D.

Dynamic Roles for IL-2-STAT5 Signaling in Effector and Regulatory CD4+ T Cell Populations

CD4⁺ Th cells are responsible for orchestrating diverse, pathogen-specific immune responses through their differentiation into a number of subsets, including T_H1, T_H2, T_H9, T follicular helper, T follicular regulatory, and regulatory T cells. The differentiation of each subset is guided by distinct regulatory requirements, including those derived from extracellular cytokine signals. IL-2 has emerged as a critical immunomodulatory cytokine that both positively and negatively affects the differentiation of individual Th cell subsets. IL-2 signals are propagated, in part, via activation of STAT5, which functions as a key regulator of CD4⁺ T cell gene programs. In this review, we discuss current understanding of the mechanisms that allow IL-2-STAT5 signaling to exert divergent effects across CD4⁺ T cell subsets and highlight specific roles for this pathway in the regulation of individual Th cell differentiation programs.

Irradiated whole-cell vaccine suppresses hepatocellular carcinoma growth in mice via Th9 cells

Liver cancer is one of the most common malignant tumors with no available satisfactory treatment. The aim of the present study was to investigate the anti-tumor effect of an irradiated hepatocellular carcinoma (HCC) whole-cell vaccine and its underlying mechanisms. Hepa1-6 and H22 HCC cell lines were irradiated in preparation for whole-cell vaccine production. Subsequently, two HCC tumor-bearing mouse models were created by injecting these Hepa1-6 and H22 cells into the abdominal skin of C57BL/6 and ICR mice, respectively. The mice were immunized with the corresponding whole-cell vaccine the next day, and then once a week until the end of the experimental period. Tumor growth, blood T helper (Th)9 cells and plasma interleukin (IL)-9 levels were monitored during the immunization period. Th9 cells were also induced by in vitro co-culture of the whole-cell vaccine with lymphocytes from the spleen and lymph nodes of the corresponding mice. Alterations of gene expression in transcription factor (TF) were determined by reverse transcription-quantitative PCR, and Th9 cells were detected using flow cytometry. The whole-cell vaccine effectively suppressed HCC tumor growth, as indicated by slower tumor growth and a smaller tumor size in the immunized group compared with the control. The percentage of blood Th9 cells and the concentration of plasma IL-9 were significantly increased in the immunized group. The whole-cell vaccine also induced Th9 cell differentiation and upregulated the expression of TFs PU.1, interferon regulatory factor 4 and basic leucine zipper transcriptional factor ATF-like. These results suggest that the irradiated HCC whole-cell vaccine inhibited tumor growth by increasing Th9 cell numbers in HCC mice

The Role of IL-9 Polymorphisms and Serum IL-9 Levels in Carcinogenesis and Survival Rate for Laryngeal Squamous Cell Carcinoma

Recent studies have described the dichotomous function of IL-9 in various cancer diseases. However, its function has still not been analysed in laryngeal squamous cell carcinoma (LSCC). In the present study, we evaluated five single nucleotide polymorphisms (SNPs) of IL-9 (rs1859430, rs2069870, rs11741137, rs2069885, and rs2069884) and determined their associations with the patients' five-year survival rate. Additionally, we analysed serum IL-9 levels using an enzyme-linked immunosorbent assay. Three hundred LSCC patients and 533 control subjects were included in this study. A significant association between the patients' survival rate and distribution of IL-9 rs1859430 variants was revealed: patients carrying AA genotype had a higher risk of dying (p = 0.005). Haplotypes A-G-C-G-G of IL-9 (rs1859430, rs2069870, rs11741137, rs2069885, and rs2069884) were associated with 47% lower odds of LSCC occurrence (p = 0.035). Serum IL-9 levels were found detectable in three control group subjects (8.99 ± 12.03 pg/mL). In summary, these findings indicate that the genotypic distribution of IL-9 rs1859430 negatively influences the five-year survival rate of LSCC patients. The haplotypes A-G-C-G-G of IL-9 (rs1859430, rs2069870, rs11741137, rs2069885, and rs2069884) are associated with the lower odds of LSCC development.

Critical Roles of Balanced T Helper 9 Cells and Regulatory T Cells in Allergic Airway Inflammation and Tumor Immunity

CD4⁺T helper (Th) cells are important mediators of immune responses in asthma and cancer. When counteracted by different classes of pathogens, naïve CD4⁺T cells undergo programmed differentiation into distinct types of Th cells. Th cells orchestrate antigen-specific immune responses upon their clonal T-cell receptor (TCR) interaction with the appropriate peptide antigen presented on MHC class II molecules expressed by antigen-presenting cells (APCs). T helper 9 (Th9) cells and regulatory T (Treg) cells and their corresponding cytokines have critical roles in tumor and allergic immunity. In the context of asthma and cancer, the dynamic internal microenvironment, along with chronic inflammatory stimuli, influences development, differentiation, and function of Th9 cells and Treg cells. Furthermore, the dysregulation of the balance between Th9 cells and Treg cells might trigger aberrant immune responses, resulting in development and exacerbation of asthma and cancer. In this review, the development, differentiation, and function of Th9 cells and Treg cells, which are synergistically regulated by various factors including cytokine signals, transcriptional factors (TFs), costimulatory signals, microenvironment cues, metabolic pathways, and different signal pathways, will be discussed. In addition, we focus on the recent progress that has helped to achieve a better understanding of the roles of Th9 cells and Treg cells in allergic airway inflammation and tumor immunity. We also discuss how various factors moderate their responses in asthma and cancer. Finally, we summarize the recent findings regarding potential mechanisms for regulating the balance between Th9 and Treg cells in asthma and cancer. These advances provide opportunities for novel therapeutic strategies that are aimed at reestablishing the balance of these cells in the diseases.

A Palette of Cytokines to Measure Anti-Tumor Efficacy of T Cell-Based Therapeutics

Cytokines are key molecules within the tumor microenvironment (TME) that can be used as biomarkers to predict the magnitude of anti-tumor immune responses. During immune monitoring, it has been customary to predict outcomes based on the abundance of a single cytokine, in particular IFN-γ or TGF-β, as a readout of ongoing anti-cancer immunity. However, individual cytokines within the TME can exhibit dual opposing roles. For example, both IFN-γ and TGF-β have been associated with pro- and anti-tumor functions. Moreover, cytokines originating from different cellular sources influence the crosstalk between CD4+ and CD8+ T cells, while the array of cytokines expressed by T cells is also instrumental in defining the mechanisms of action and efficacy of treatments. Thus, it becomes increasingly clear that a reliable readout of ongoing immunity within the TME will have to include more than the measurement of a single cytokine. This review focuses on defining a panel of cytokines that could help to reliably predict and analyze the outcomes of T cell-based anti-tumor therapies.

Antibody-based delivery of interleukin-9 to neovascular structures: Therapeutic evaluation in cancer and arthritis

Interleukin-9 is a cytokine with multiple functions, including the ability to activate group 2 innate lymphoid cells, which has been postulated to be therapeutically active in mouse models of arthritis. Similarly, interleukin-9 has been suggested to play an important role in tumor immunity. Here, we describe the cloning, expression, and characterization of three fusion proteins based on murine interleukin-9 and the F8 antibody, specific to the alternatively spliced EDA domain of fibronectin. EDA is strongly expressed in cancer and in various arthritic conditions, while being undetectable in the majority of healthy organs. Interleukin-9-based fusion proteins with an irrelevant antibody specific to hen egg lysozyme served as negative control in our study. The fusion proteins were characterized by quantitative biodistribution analysis in tumor-bearing mice using radioiodinated protein preparations. The highest tumor uptake and best tumor:organ ratios were observed for a format, in which the interleukin-9 moiety was flanked by two units of the F8 antibody in single-chain Fv format. Biological activity of interleukin-9 was retained when the payload was fused to antibodies. However, the targeted delivery of interleukin-9 to the disease site resulted in a modest anti-tumor activity in three different murine models of cancer (K1735M2, CT26, and F9), while no therapeutic benefit was observed in a collagen induced model of arthritis. Collectively, these results confirm the possibility to deliver interleukin-9 to the site of disease but cast doubts about the alleged therapeutic activity of this cytokine in cancer and arthritis, which has been postulated in previous publications.

Targeting ubiquitin signaling for cancer immunotherapy

Cancer immunotherapy has become an attractive approach of cancer treatment with tremendous success in treating various advanced malignancies. The development and clinical application of immune checkpoint inhibitors represent one of the most extraordinary accomplishments in cancer immunotherapy. In addition, considerable progress is being made in understanding the mechanism of antitumor immunity and characterizing novel targets for developing additional therapeutic approaches. One active area of investigation is protein ubiquitination, a post-translational mechanism of protein modification that regulates the function of diverse immune cells in antitumor immunity. Accumulating studies suggest that E3 ubiquitin ligases and deubiquitinases form a family of potential targets to be exploited for enhancing antitumor immunity in cancer immunotherapy.

ILC2-derived IL-9 inhibits colorectal cancer progression by activating CD8+ T cells

Group 2 innate lymphoid cells (ILC2s), characterized by secretion of type 2 cytokines, regulate multiple immune responses. ILC2s are found in different tumor tissues, and ILC2-derived interleukin (IL)-4, IL-5, and IL-13 act on the cells in tumor microenvironment to participate in tumor progression. ILC2s are abundant in colorectal cancer (CRC) tissue, but the role of ILC2s in CRC remains unclear. In this study, we found that the percentage of ILC2s was higher in CRC tissue than in the adjacent normal tissue and that these ILC2s were the dominant IL-9-secreting cell-subsets in CRC tissue, as shown by flow cytometry analysis. ILC2s-derived IL-9 could activate CD8⁺ T cells to inhibit tumor growth, while anti-IL-9 reversed this effect. In vivo experiments showed that neutralizing ILC2s promoted tumor growth, while tumor inhibition occurred by intravenous injection of IL-9. In conclusion, our results demonstrated that ILC2-derived IL-9 could activate CD8⁺ T cells to promote anti-tumor effects in CRC.

Anti-Tumorigenic Activities of IL-33: A Mechanistic Insight

Interleukin-33 (IL-33) is an epithelial-derived cytokine that can be released upon tissue damage, stress, or infection, acting as an alarmin for the immune system. IL-33 has long been studied in the context of Th2-related immunopathologies, such as allergic diseases and parasitic infections. However, its capacity to stimulate also Th1-type of immune responses is now well established. IL-33 binds to its specific receptor ST2 expressed by most immune cell populations, modulating a variety of responses. In cancer immunity, IL-33 can display both pro-tumoral and anti-tumoral functions, depending on the specific microenvironment. Recent findings indicate that IL-33 can effectively stimulate immune effector cells (NK and CD8⁺ T cells), eosinophils, basophils and type 2 innate lymphoid cells (ILC2) promoting direct and indirect anti-tumoral activities. In this review, we summarize the most recent advances on anti-tumor immune mechanisms operated by IL-33, including the modulation of immune checkpoint molecules, with the aim to understand its potential as a therapeutic target in cancer.

The outstanding antitumor capacity of CD4+ T helper lymphocytes

Over the past decades, tumor-resident immune cells have been extensively studied to dissect their biological functions and clinical roles. Tumor-infiltrating CD8⁺ T cells, because of their cytotoxic and killing ability, have been under the spotlight for a long time, whereas CD4⁺ T cells are considered just a supporting actor in the field of cancer immunotherapy. Until recently, accumulating evidence has demonstrated the ability of CD4⁺ T cells in eradicating solid tumors, and their functions in mediating antitumor immunity have been investigated in various orientations. In this review, we highlight the pivotal role of CD4⁺ T cells in eliciting vigorous antitumor immune responses, summarize key signaling axes and molecular networks behind these antitumor functions, and also propose possible targets and promising strategies which might translate into more efficient immunotherapies against human cancers.

Molecular Aspects and Future Perspectives of Cytokine-Based Anti-cancer Immunotherapy

Cytokine-based immunotherapy is a promising field in the cancer treatment, since cytokines, as proteins of the immune system, are able to modulate the host immune response toward cancer cell, as well as directly induce tumor cell death. Since a low dose monotherapy with some cytokines has no significant therapeutic results and a high dose treatment leads to a number of side effects caused by the pleiotropic effect of cytokines, the problem of understanding the influence of cytokines on the immune cells involved in the pro- and anti-tumor immune response remains a pressing one. Immune system cells carry CD makers on their surface which can be used to identify various populations of cells of the immune system that play different roles in pro- and anti-tumor immune responses. This review discusses the functions and specific CD markers of various immune cell populations which are reported to participate in the regulation of the immune response against the tumor. The results of research studies and clinical trials investigating the effect of cytokine therapy on the regulation of immune cell populations and their surface markers are also discussed. Current trends in the development of cancer immunotherapy, as well as the role of cytokines in combination with other therapeutic agents, are also discussed.

Measuring Cancer Hallmark Mediation of the TET1 Glioma Survival Effect with Linked Neural-Network Based Mediation Experiments

This paper examines the effect of TET1 expression on survival in glioma patients using open-access data from the Genomic Data Commons. A neural network-based survival model was built on expression data from a selection of genes most affected by TET1 knockdown with a median cross-validated survival concordance of 82.5%. A synthetic experiment was then conducted that linked two separately trained neural networks: a multitask model estimating cancer hallmark gene expression from TET1 expression, and a survival neural network. This experiment quantified the mediation of the TET1 survival effect through eight cancer hallmarks: apoptosis, cell cycle, cell death, cell motility, DNA repair, immune response, two phosphorylation pathways, and a randomized gene sets. Immune response, DNA repair, and apoptosis displayed greater mediation than the randomized gene set. Cell motility was inversely associated with only 12.5% mediated concordance. We propose the neural network linkage mediation experiment as an approach to collecting evidence of hazard mediation relationships with prognostic capacity useful for designing interventions.

Th9 cells in allergic diseases: A role for the microbiota?

Since their discovery about 10 years ago, Th9 cells have been increasingly linked to allergic pathologies. Within this review, we summarize the current knowledge on associations between Th9 cells and allergic diseases and acknowledge Th9 cells as important targets in future treatment of allergic diseases. However, until today, it is not fully understood how these Th9 cell responses are modulated. We describe current literature suggesting that these Th9 cell responses might be stimulated by microbial species such as Staphylococcus aureus and Candida albicans, while on the other hand, microbial and dietary compounds such as retinoic acid (RA), butyrate and vitamin D show suppressive capacity on allergy-related Th9 responses. By reviewing this recent research, we provide new insights into the modulating capacity of the microbiota on Th9 cell responses. Consequently, microbial and dietary factors may be used as innovative tools to target Th9 cells in the treatment of allergic diseases. However, further research is needed to elucidate the mechanisms behind these interactions in order to translate this knowledge into clinical allergy settings.

IL-9 and IL-9-producing cells in tumor immunity

Abstract

Interleukin (IL)-9 belongs to the IL-2Rγc chain family and is a multifunctional cytokine that can regulate the function of many kinds of cells. It was originally identified as a growth factor of T cells and mast cells. In previous studies, IL-9 was mainly involved in the development of allergic diseases, autoimmune diseases and parasite infections. Recently, IL-9, as a double-edged sword in the development of cancers, has attracted extensive attention. Since T-helper 9 (Th9) cell-derived IL-9 was verified to play a powerful antitumor role in solid tumors, an increasing number of researchers have started to pay attention to the role of IL-9-skewed CD8⁺ T (Tc9) cells, mast cells and Vδ2 T cell-derived IL-9 in tumor immunity. Here, we review recent studies on IL-9 and several kinds of IL-9-producing cells in tumor immunity to provide useful insight into tumorigenesis and treatment.

Changes and significance of T helper-9 cells and interleukin-9 in patients with atherosclerotic chronic lower limb ischemia: Effect on IL-17 release

OBJECTIVES

Atherosclerosis is considered as a chronic inflammatory disorder where the central role of T cells in its pathogenesis is well known. T helper-9 cells have a distinctive effect upon the inflammatory processes. They stimulate macrophages via secretion of their cytokine interleukin-9. Based on its known involvement with other inflammatory disorders, we hypothesized that interleukin-9 might be associated with the inflammatory limb of peripheral atherosclerotic disease.

METHODS

We tested this hypothesis on peripheral blood mononuclear cells (PBMCs) and freshly resected arterial tissues from 84 patients with peripheral arterial occlusive disease (PAOD) and 50 non-atherosclerotic subjects. A number of experimental methods were used including flow cytometry analysis of T helper-9 cells using anti-CD3, anti-CD4, and anti-interleukin-9monoclonal antibodies as well as real-time polymerase chain reaction for the assessment of gene expression of interleukin-9. In addition, circulating serum levels of interleukin-9 were measured using enzyme linked immunosorbent assay. We also evaluated the ability of recombinant interleukin-9 to modulate IL-17 release in cultured isolated CD3+ T cells with relation to atherosclerotic disorder in vitro.

RESULTS AND CONCLUSIONS

Here we report increased percentages of T helper-9 cells and interleukin-9 levels in patients with chronic lower limb atherosclerotic ischemia, compared to healthy controls. Through investigation of different atherosclerotic patient populations with different disease stages, we found elevated interleukin-9 level both systemically and within the lesion and increased expression of cells in severe disease stages. The current study also revealed enhanced expression of mRNA levels of interleukin-9 within the atherosclerotic lesion when compared with non-atherosclerotic vessels. Levels of released IL-17 in CD3+ T cell culture supernatants supplemented with interleukin-9 were significantly positively correlated in the enrolled patients. The results suggest a role for T helper-9 cells and IL-9 in atherosclerotic process, potentially involving IL-17-mediated mechanisms. Indeed, we found that interleukin-9 promoted IL-17 release in PBMCs, with a particularly marked response in severe disease.

Galectin Domain Containing Protein from Haemonchus contortus Modulates the Immune Functions of Goat PBMCs and Regulates CD4+ T-Helper Cells In Vitro

Galectins are glycan-binding proteins that are widely expressed and distributed in mammalian tissues as well as cells of innate and adaptive immune responses. CD4+ T-helper cells differentiate into effector subsets in response to cytokines. T helper 9 cells are one of the recently described subsets of effector T cells that are relatively new and less studied. In this study, galectin domain containing protein from Haemonchus contortus (Hc-GDC) was cloned, expressed in pET32a, and immunoblotting was performed. Localization of recombinant (r)Hc-GDC on outer and inner surface of H. contortus worm and binding with goat Peripheral Blood Mononuclear cells (PBMCs) were performed using immunofluorescence assay. Moreover, effects of rHc-GDC on proliferation, apoptosis, cell migration, and the nitric oxide production in goat PBMCs were evaluated. Furthermore, modulatory effects of rHc-GDC on production of Th1, Th2, and Th9 cells were evaluated by flowcytometry and on interferon gamma, interleukin (IL)-4 and IL-9 were evaluated by quantitative real-time polymerase chain reaction. The results demonstrated that rHc-GDC was successfully cloned, expressed in expression vector as well as in the gut surface of adult H. contortus worm and successful binding with PBMCs surface were observed. Immunoblotting results revealed that rHc-GDC is an important active protein of H. contortus excretory and secretory products. Moreover, the interaction of rHc-GDC with host cells increased the production of Th2, Th9 cells, IL4, IL-9, PBMC proliferation, nitric oxide, and cell migration. No effects of rHc-GDC were observed on PMBC apoptosis, production of Th1 cells, and secretions of IFN- and IL-10 cytokines. These findings indicate that recombinant GDC protein from H. contortus modulates the immune functions of goat PBMCs and has the potential to enhance protective immunity by inducing T helper-9-derived IL-9 in vitro.

Janus or Hydra: The Many Faces of T Helper Cells in the Human Tumour Microenvironment

CD4+ T helper (T_H) cells are key regulators in the tumour immune microenvironment (TIME), mediating the adaptive immunological response towards cancer, mainly through the activation of cytotoxic CD8+ T cells. After antigen recognition and proper co-stimulation, naïve T_H cells are activated, undergo clonal expansion, and release cytokines that will define the differentiation of a specific effector T_H cell subtype. These different subtypes have different functions, which can mediate both anti- and pro-tumour immunological responses. Here, we present the dual role of T_H cells restraining or promoting the tumour, the factors controlling their homing and differentiation in the TIME, their influence on immunotherapy, and their use as prognostic indicators.

P-MAPA and Interleukin-12 Reduce Cell Migration/Invasion and Attenuate the Toll-Like Receptor-Mediated Inflammatory Response in Ovarian Cancer SKOV-3 Cells: A Preliminary Study

Immunotherapies have emerged as promising complementary treatments for ovarian cancer (OC), but its effective and direct role on OC cells is unclear. This study examined the combinatory effects of the protein aggregate magnesium-ammonium phospholinoleate-palmitoleate anhydride, known as P-MAPA, and the human recombinant interleukin-12 (hrIL-12) on cell migration/invasion, apoptosis, toll-like receptor (TLR)-mediated inflammation, and cytokine/chemokine profile in human OC cell line SKOV-3. P-MAPA and IL-12 showed cancer cell toxicity under low doses after 48 h. Although apoptosis/necrosis and the cell cycle were unchanged by the treatments, P-MAPA enhanced the sensitivity to paclitaxel (PTX) and P-MAPA associated with IL-12 significantly reduced the migratory potential and invasion capacity of SKOV-3 cells. P-MAPA therapy reduced TLR2 immunostaining and the myeloid differentiation factor 88 (MyD88), but not the TLR4 levels. Moreover, the combination of P-MAPA with IL-12 attenuated the levels of MyD88, interferon regulatory factor 3 (IRF3) and nuclear factor kappa B (NF-kB p65). The IL-12 levels were increased and P-MAPA stimulated the secretion of cytokines IL-3, IL-9, IL-10, and chemokines MDC/CCL22 and, regulated on activation, normal T cells expressed and secreted (RANTES)/CCL5. Conversely, combination therapy reduced the levels of IL-3, IL-9, IL-10, MDC/CCL22, and RANTES/CCL5. Collectively, P-MAPA and IL-12 reduce cell dynamics and effectively target the TLR-related downstream molecules, eliciting a protective effect against chemoresistance. P-MAPA also stimulates the secretion of anti-inflammatory molecules, possibly having an immune response in the OC microenvironment.

TH9, TH17, and TH22 Cell Subsets and Their Main Cytokine Products in the Pathogenesis of Colorectal Cancer

In recent years, several newly identified T helper (T_H) cell subsets, such as T_H9, T_H17, and T_H22 cells, and their respective cytokine products, IL-9, IL-17, and IL-22, have been reported to play critical roles in the development of chronic inflammation in the colorectum. Since chronic inflammation is a potent driving force for the development of human colorectal cancer (CRC), the contributions of T_H9/IL-9, T_H17/IL-17, and T_H22/IL-22 in the pathogenesis of CRC have recently become an increasingly popular area of scientific investigation. Extensive laboratory and clinical evidence suggests a positive relationship between these new T_H subsets and the growth and formation of CRC, whereas, administration of IL-9, IL-17, and IL-22 signaling inhibitors can significantly alter the formation of colorectal chronic inflammation or CRC lesions in animal models, suggesting that blocking these cytokine signals might represent promising immunotherapeutic strategies. This review summarizes recent findings and currently available data for understanding the vital role and therapeutic significance of T_H9/IL-9, T_H17/IL-17, and T_H22/IL-22 in the development of colorectal tumorigenesis.

Th9 cytokines curb cervical cancer progression and immune evasion

Cervical cancer is one of the most common cancers among women in developing countries. Persistent infection with high-risk human papillomavirus (HPV) is the major determinant for the development of cervical cancer. Role of newly discovered T helper 9 (Th9) cells in cervical cancer pathogenesis is yet unfolded. In this study, we observed a huge infiltration of PU.1⁺ cells and overrepresentation of IL-9R in tissue biopsy specimens of CIN patients in cervical cancer cases. Treatment with Th9 signatory cytokines, IL-9 and IL-21, suppressed proliferation, enhanced apoptosis and stimulated the expression of MHC I and e-cadherin on HeLa cell lines. Th9 thus seems enhance antitumor immune response through T cell cytotoxicity and play crucial role in a controlling malignant cell transformation. Therefore, this study helps in firmer understanding of relevance of Th9 in cervical cancer immunity.

CD4 T cells target colorectal cancer antigens upregulated by oxaliplatin

Immune checkpoint blockade has proven its efficacy in hypermutated subtypes of metastatic colorectal cancers (mCRC). Immunogenic potential can also be observed with conventional chemotherapies, but this property has never been explored thoroughly in CRC patients. The CRC therapeutic arsenal includes oxaliplatin, a well-characterized platinum drug already described as immunogenic. Here, we investigated the impact of the oxaliplatin-based treatment on mCRC immunopeptidome. We demonstrated that oxaliplatin-resistant CRC cell lines overexpressed telomerase reverse transcriptase (TERT), colorectal-associated-tumor antigen-1 (COA-1) and mesothelin tumor-associated antigens. We identified new HLA class-II-restricted and promiscuous peptides derived from COA-1 and mesothelin. The two naturally processed peptides COA-1_331-345 and Meso_366-380 appear to be the most immunogenic in mCRC patients. A prospective cohort of 162 mCRC patients enabled us to explore the impact of oxaliplatin exposure on the antitumor-specific immune response. Interestingly, chemotherapy-naive mCRC patients present high immune CD4 T-cell responses directed against TERT, COA-1 and mesothelin-derived peptides. These antitumor T-cell responses were maintained after 3 months of oxaliplatin-based treatment. Altogether, these findings highlight the interest of immunostimulatory agents to improve the management of chemoresistant mCRC patients. Finally, the high frequency of immune responses targeting the new immunogenic peptides derived from COA-1 and mesothelin support their use in immunomonitoring strategies.

STAT3, a Master Regulator of Anti-Tumor Immune Response

Immune cells in the tumor microenvironment regulate cancer growth. Thus cancer progression is dependent on the activation or repression of transcription programs involved in the proliferation/activation of lymphoid and myeloid cells. One of the main transcription factors involved in many of these pathways is the signal transducer and activator of transcription 3 (STAT3). In this review we will focus on the role of STAT3 and its regulation, e.g. by phosphorylation or acetylation in immune cells and how it might impact immune cell function and tumor progression. Moreover, we will review the ability of STAT3 to regulate checkpoint inhibitors.

Emerging Roles of Th9 Cells as an Anti-tumor Helper T Cells

The newly discovered Th9 cells are the distinct subset of CD4⁺ T helper (Th) cells, which are involved in various pathophysiological conditions of an immune response. In addition to its role in allergic inflammation and elimination of extracellular pathogens, Th9 cells were found to play a key role in inducing anti-tumor immune response. Precisely, the anti-tumor functions of Th9 cells were found to be superior as compared to Th1 and other Th subsets. Th9 cells eliminate tumors via activating innate and adaptive immune cells, and in particular, generating a profound effector cytotoxic T lymphocyte (CTL) response against neo antigens. In addition, it was proposed that Th9 cells were found to induce effector functions of innate cells like dendritic cells, mast cells and NK cells, which further promote a robust anti-tumor immune response. In this review, we highlight the recent advances in differentiation and functions of Th9 cells in anti-tumor immunity.

Potential Mechanisms of T Cell-Mediated and Eosinophil-Independent Bronchial Hyperresponsiveness

Bronchial asthma is a chronic disease characterized by reversible airway obstruction, mucus production, and bronchial hyperresponsiveness (BHR). Although Th2 cell-mediated eosinophilic inflammation is an important disease mechanism in the majority of patients with bronchial asthma, recent studies suggest the possible development of Th2-independent airway inflammation and BHR. These non-Th2 endotype patients seem to consist of multiple subgroups, and often do not respond to inhaled corticosteroids. Therefore, to understand the pathogenesis of asthma, it is important to characterize these non-Th2 subgroups. Recently, we demonstrated that Th9 cells induce eosinophil infiltration and eosinophil-independent BHR, and Th9 cells-mediated BHR may be resistant to glucocorticoid. In this review, we summarize the contribution of several T cell subsets in the development of bronchial asthma and introduce our recent study demonstrating Th9 cell-mediated and eosinophil-independent BHR.